The invention relates to electric incandescent lamps having flat foil filaments suspended between a center post conductor and a ring conductor.
Prior art includes U.S. Pat. No. 1,305,295 by McKay which features a flat circular foil filament mounted between grooved lead-in members on opposite sides of the filament, U.S. Pat. No. 2,319,338 by Mulder which features ring conductors supported by vertical post conductors, U.S. Pat. No. 617,725 by Goddard which features a grooved heat element with integral projections on the edges thereof, U.S. Pat. No. 3,788,721 of Vause featuring a metal web element, and U.S. Pat. No. 4,144,473 of Almer which features a hollow cylindrical filament with perforations.